<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <!-- 标签名.类名$*n -->

    <div id="d1"></div>
    <div id="d2"></div>
    <div id="d3"></div>
    <div id="d4"></div>

    <ul>
        <li class="a1"></li>
        <li class="a2"></li>
        <li class="a3"></li>
        <li class="a4"></li>
        <li class="a5"></li>
    </ul>

    <p id="s1"></p>
    <p id="s2"></p>
    <p id="s3"></p>
    <p id="s4"></p>
    <p id="s5"></p>

    <div class="ff1"></div>
    <div class="ff2"></div>
    <div class="ff3"></div>
    <div class="ff4"></div>
</body>
</html>